The overall rate of atrial fibrillation was 8.4 cases per 1,000 individuals per year; this according to data collected from the study participants over many years. With each additional drink consumed per day, an additional five percent increase in annual risk accompanied. Plus, an additional daily drink was also linked to a small but significant enlargement of the left atrium, indicating a potential location of damage from alcohol consumption that could be responsible for alcohol-induced atrial fibrillation, at least in part.
The irregular pumping of blood that characterizes atrial fibrillation can lead to blood clots, making the condition a serious risk factor for stroke. Researchers are still unsure exactly how alcohol consumption impacts atrial fibrillation risk. Other known risk factors for atrial fibrillation include diabetes, hypertension, coronary artery disease, and more.
Despite Marcus’ recent findings, the confusing and somewhat contradictory relationship between alcohol and heart health still remains, and Marcus and his team are not strangers to the potential positive effects alcohol can have on heart health. Earlier in 2016, results from a study they conducted showed that moderate drinking can reduce the risk of heart attack, even while simultaneously increasing the risk of atrial fibrillation: “patients in counties permitting alcohol sales were more likely to have atrial fibrillation but less likely to have heart attacks and congestive heart failure.”
"I'm constantly trying to remind people that there are various forms of heart disease and not all are related to heart attack," said Marcus. "Atrial fibrillation is growing in importance as our success in preventing heart attack grows."
Sources: University of California San Francisco, American Rhythm Society